Night-vision scopes for rifles intensify low-level visible and/or infrared light from a dimly lit scene so that the scene is visible to the human eye. The typical night-vision scope has an image-intensifier system that consists of an optics portion and a control portion. The optics portion comprises an objective lens in optical communication with an image intensifier device that includes a photocathode. The objective lens images light (photons) from the low-light scene onto the photocathode. In response, the photocathode emits photo-electrons in proportion to the amount of light imaged at each photocathode location, thereby forming an electron pattern representative of the low-level scene image. The emitted photo-electrons are then accelerated by a first large voltage potential (e.g., 5000 volts) through a micro channel plate, which acts to multiply the number of electrons via secondary cascaded emission. The multiplied electrons move toward a phosphor screen via a second voltage potential, which converts each incident electron into a corresponding photon. The result is a visible-light pattern representative of the dimly lit scene and that is visible to the human eye.
The control portion of the image intensifier system includes electronic circuitry and a power source necessary for controlling and powering the image intensifier portion of the night vision system. Since night-vision scopes are portable, the power source is a battery.
There are three basic approaches to providing the necessary electrical power via battery to operate the image intensifier of a night-vision scope. The first is to use two AA 1.5-volt batteries in series to provide 3 volts to the electronic circuitry. The second is to use a single 3-volt lithium battery (e.g., a DL123 battery). The third is to use one AA 1.5-volt battery in conjunction with a step-up circuit, such as described in U.S. Pat. No. 6,806,683 to Saldana (the '683 patent).
The '683 patent discloses a battery adapter system that uses a battery housing in combination with a step-up circuit mounted in the battery housing. The battery adapter system allows a night-vision device to use a single AA 1.5-volt battery. The motivation behind the '683 patent is that most missions where night-vision devices are used last less than 24 hours and so do not require two AA batteries. Because the single 1.5-volt battery provides the 3 volts needed, it is used up quicker than two batteries, so that the single battery is used nearly to or up to its life's end.
There are a number of disadvantages to the above approaches. First, the use of two AA 1.5-volt batteries in series tends to be wasteful and adds weight to the night scope. The second approach of using a single DL123 3-volt lithium battery would not be problematic were it not for the fact that prior art night scopes are adapted to use only one DL123 battery or only one or two AA batteries, but are not adapted to accommodate both types of batteries.
The third approach of using a single AA battery in combination with a step-up circuit according to the '683 patent has several shortcomings. A first shortcoming is that the '683 patent battery adapter system only accommodates one type of battery. A second shortcoming is that there is no description or teaching of how the battery adapter is integrated with a night-vision scope. A third shortcoming is that there is no description or teaching of the particularly rigorous military specifications the battery adapter system must meet if it is to be used for military equipment.